I am trying to decide between investing in Vanguard VCN with its 0.27 MER, or TDB900 with its 0.33 MER.I am investing in CDN $, and already have sufficient exposure to US$ currency fluctuations with other holdings.

But - Is there a difference between the two in terms of CDN to US$ currency risk? There must be but I am having a blank moment figuring out exactly what that is.

Can someone explain for me?

(BTW, I already own some of both of these funds, but VCN is already in the account I am buying in, and except for potential currency risk, I would buy that one.)